I've been struggling trying to keep our 2 goldens dog hair from the coils of our 8 year old Kenmore side by side with "W" compressor coils, but like everyone else was unable to clean past the first set of coils.
I came up with this solution that worked to get much of the big stuff, hair and bunnies, off of the further back coils. Not perfect but much better than nothing.
Removing the back lower panel I was able to snake a crevice attachment from our vacuum down the right side of the coils (left side looking from back)
Looking from front"
I made a compressed air contraption to blow the dust/hair across the coils using a compressed air nozzle that I added a 10" long tube and a 90 degree deflector
From the front of the fridge, on the left side of the coils, I snaked the compressed air nozzle towards the back and started directing the air stream blowing towards the vacuum crevice tool at the opposite side of the coils.
The compressed air dislodged the hair/dust enough that the vacuum was able to **** it away. Again, not perfectly but certainly much better than I was able to clean the coils in the past.
I suppose you could use a can of compressed air and add some sort of deflector if you don't have a compressor.
I then got to thinking how to prevent the dust from accumulating on the coils, I'm going to try an air conditioner filter. I cut it slightly oversized to fit the front opening then split it in half to make it thinner for more air flow.
Picture taken before making the filter thinner.
For years I had my calendar remind me monthly to vacuum the coils but now hopefully I'll be able to simply change the air filter.